Recent studies in our laboratory have suggested novel approaches to melanoma progression that could serve as the basis for the development of novel biomarkers and therapeutic targets for melanoma. In this proposal, we aim to conduct a biomarker analysis in a prospective cohort, the randomized intergroup trial of adjuvant therapy with high-dose interferon alpha (Eastern Cooperative Group trial E1690). We aim to validate the role of a multi-marker prognostic assay (with confirmed prognostic impact in two distinct cohorts) in the ECOG cohort. Secondly, we aim to validate the functional role of the fetal Alzheimer (FALZ) gene in the progression of melanoma in murine models. Third, we aim to identify microRNAs (miRNAs) with prognostic significance in a large cohort of melanoma patients. Importantly, these diverse targets were identified by virtue of their differential expression in profiling studies of the same tissue cohort of nevi, primary and metastatic melanomas. Our three specific aims are: Aim 1: To perform a molecular prognostic factor analysis on the E1690 cohort. In this aim, we propose correlative studies on tissues from the patient population enrolled in the E1690 trial. We propose to validate the prognostic role of a multi-marker immunohistochemical assay in the E1690 cohort, and to determine its predictive role in assessing benefit to adjuvant therapy with interferon alpha. Aim 2: To validate the role of the FALZ gene in melanoma progression in murine models. We will characterize the functional importance of the FALZ gene on the progression of melanoma by examining the role of targeted siRNA-mediated suppression of FALZ in the progression of human melanoma in vivo. Aim 3: To develop microRNA profiles in the prognostic assessment of primary melanoma. Recent results obtained in our laboratory have identified differentially expressed miRNAs in the known transitions in melanoma progression. We will examine the prognostic role of ten miRNAs using TaqMan analysis in a large cohort of melanoma patients. If successful, these studies will validate a multi-marker prognostic assay for melanoma, firmly establish a role for FALZ in promoting melanoma metastasis, and identify miRNAs with prognostic significance in melanoma.